Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County

Client's Request: I am about average in composting: mix a balance of brown and green; no weeds, seeds, meat, dairy products; moist like a squeezed-out sponge; and rotate/turn over. The internal heat will promote digestion – and result in some “steam.”

With my small garden, the beds fill to overflowing. Thus, I do not always apply all my compost. My question: Can compost “go bad?” if it dries out? If it is not used for months? Thank you!

MGCC Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk with your compost question. You asked if compost would go bad if it dries out. The answer is not really, but it can change. If it completely dries, it may become a little difficult to wet the compost. You might want to moisten it before putting it into your garden. 

When compost completely dries, many of the microorganisms (bacterial and fungi) will die, but some will form "survival capsules" or spores that will keep them alive until better conditions come along. Also, good soil is teeming with microorganisms that will "repopulate" the compost, and will continue to break down compost added to the soil. 

So, compost that has dried is fine to use in your garden. It just needs some management. And congratulations on being a successful composter!

Please let us know if you have more questions.

Help Desk of the UC Master Gardener Program of Contra Costa County (SEH)

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Note: The  UC Master Gardeners Program of Contra Costa's Help Desk is available almost year-round to answer your gardening questions.  Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone:  (925) 608-6683, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog  (//ucanr.edu/blogs/CCMGBlog/)

Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County

Apricot Tree Showing Signs of Brown Rot
by Chantal Guillemin , Master Gardener

Request:  My Royal (Blenheim) apricot tree usually produces delicious fruit, but this year almost all had brown discoloration. Globs of golden sap ooze out in many places along branches and the ends of some branches have brown, withered leaves and dead flowers. What kind of disease is affecting my apricot tree?  What can I do about it?

Response:  Thanks for contacting the Help Desk of the UC Master Gardener Program of Contra Costa County about the problems with the brown spots appearing on your apricot fruit.

Expanding dark brown, firm, circular spots on apricots are symptomatic of a very common and serious disease of stone fruit called brown rot. The exudation (oozing) of sticky droplets of gum (sap) from the base of dead flowers and the bark of infected twigs is further indication that Monolinia spp., the brown rot fungus, is present on your apricot tree. Brown rot can also infect other stone fruit such as almond, peach, plum, cherry, nectarine and quince (a pome fruit).

The first symptom of brown rot is the browning and withering of blossoms. These infected blossoms cling to twigs for months. Cankers, which are sunken brown areas, may develop around twigs at the base of infected flowers, causing leaves at tips of twigs to become dark brown and shrivel up.

Brown Rot on Apricot Fruit
Photo by William W. Coates, courtesy UC Statewide IPM Program

Monolinia survives from the previous season as velvety, grey or tan tufts of spores. After rains are over, these tiny spores remain on host blossoms, peduncles (stalk where flower attach), and twigs. They, along with mummified fruit remaining on the tree or on the ground, are the sources (inoculum) for blossom infection. This inoculum can germinate in 2-4 hours and spread to blossoms by air current, rain splash and insects. If flowers are not wet from rain or irrigation, very little blossom blight will develop. Monolinia can also affect green fruit in early summer, and as most rot develops during the month before harvest, fruit is most susceptible to brown rot as it ripens. Fruit rot can develop while fruit is on the tree or post harvest while it is in storage. You can minimize post harvest brown spot by chilling harvested apricots destined for home consumption.

Gardeners in Contra Costa County can practice the following sanitation measures to decrease the spread of brown rot fungal disease:  frequent checking of stone fruit trees for signs of brown rot, timely and appropriate pruning, furrow or drip irrigating versus overhead sprinklers, and planting disease tolerant varieties.

Inspect your apricot and other stone fruit trees nearby often for symptoms of brown rot. Do this during the bloom period, as fruit turn green, and when they begin to ripen. Consider harvesting fruit before it is ripe but once it is soft will lessen the risk of brown rot. After harvest, remove all fruit left on trees or destroy them because they are potential overwintering sites for brown rot. Ensuring that gardening sanitation tasks are performed on a regular basis will go a long way to minimizing the development of spores from mummified fruit hidden beneath weeds and debris on the ground.

As for apricot trees, pruning should never be done during winter dormancy. That's our wet season, and atmospheric moisture carries airborne spores and pathogens. Apricot and cherry trees are particularly susceptible to Eutypa dieback, a disease which causes whole branches to wither away. Do not inflict pruning wounds on apricot trees at this time. Pruning diseased twigs and dead blossoms still clinging to branches of apricot trees should be done after leaves drop but before the first fall rains.

Other stone fruit require the same removal of infected plant tissue but this can be done as soon as these are detected. Burn, bury or bag all diseased branches and leaves. Destruction of these affected parts and the removal of mummies from the tree and from beneath the tree prevents the buildup of brown rot inoculum. This applies to flowering cherry, plum and quince as well. Do not put diseased plant parts in compost. Remove broken or diseased branches. Prune trees from the time they are planted to allow good ventilation in the canopy.  

Avoid wetting blossoms, foliage, and fruit during irrigation by using furrow or drip irrigation. As far as prunes are concerned, drying them immediately after harvest kills the brown rot fungus.

Some plant varieties are known to be least susceptible to brown rot. Apricot cultivars Tilton, Harcot, and Harglow are touted to have some brown rot resistance.  Royal, Blenheim, Perfection, and Derby Roal are most susceptible to this fungal infection.

If left unmonitored, brown rot fungal infection of apricots and other stone fruit can thwart homeowner's plans for a harvest of healthy fruit. Familiarization with brown rot symptoms and taking action to remove sources of brown rot spores can alleviate the problem of brown rot fungal infection on apricots and other stone fruit.

For additional information, you can also consult:
UCANR publication 7259, Apricots: Calendar of Operations for Home Gardeners;
UCANR publication Pests in Garden and Landscapes – Brown Rot Monilinia spp.;
UCANR publication 3332, Pests of the Garden and Small Farm, pp 144-145; 
UCANR publication 3382, California Master Gardener Handbook Chapter 16
UCANR publication 3311, Postharvest Technology of Horticultural Crops; 
UCANR publication 3345, Diseases of Temperate Zone Tree Fruit and Nut Crops; 
UCANR publication 3485, The Home Orchard

Those not available as free download UC publications are often available at your local branch library or by mail order from UCANR.

Please do not hesitate to contact the MGCC'S Help Desk if you have further questions and/or need recommendations.

Help Desk of the UC Master Gardener Program of Contra Costa County (CCG)

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Note: The  UC Master Gardeners Program of Contra Costa's Help Desk is available almost year-round to answer your gardening questions.  Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone:  (925) 608-6683, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog  (http://ucanr.edu/blogs/CCMGBlog/)

Help for Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County

Subject: Recommendations for Small Backyard Trees
 
Client's Request:  Hello! We have a west facing small backyard in central County that gets scorched with sun. I'd really love a small tree to plant along the fence to help shade the backyard. Ideally, the tree is drought tolerant, evergreen, not messy, and not poisonous. Thank you!

MGCC Help Desk Response:  Thank you for contacting the UC Master Gardener Program Help Desk with questions about plant selection. You have a west-facing yard in central County. I can commiserate--I, too, have a west-facing backyard in central County. I know how hot it gets. 

You are looking for an evergreen tree that is drought tolerant, not messy, and not poisonous. Be aware that all trees and shrubs will make some litter. Evergreens drop their leaves throughout the year, often with heavier leaf drop during certain periods. Many have flowers or fruit that drop. 

There are many plants you can choose from that fulfill at least most of your criteria. For example, Arbutus unedo (strawberry tree) is a good tree, but it has fruit and can be messy over nearby paved surfaces. Prunus illicifolia (hollyleaf cherry) can be grown as a small tree or shrub, but again, it has fruit. Sweet Bay (Laurus nobilis) can also be grown as a small tree or a shrub and it will provide Bay leaves for cooking. Responding to your request in the middle of summer, we can all appreciate the flowering Crepe myrtles (Lagerstroemia), but they are deciduous and often require appropriate pruning each winter. You may also want to consider some varieties of citrus as they are usually not deciduous, produce edible fruit, but they are not drought resistant.

There are several good resources for lists of trees. Sunset Western Garden Book has lists of plants that fulfill various purposes, such as plants for hedges, small trees, plants for waterwise gardens, etc. You can find this book at your local library (or some examples here). The Contra Costa Water District has a great resource website that can help with plant selection and guidance for watering: http://www.contracosta.watersavingplants.com/. Another resource for selecting trees based on various criteria is the website from Cal Poly: https://selectree.calpoly.edu/search-trees-by-characteristics/.

You will need to do a lot of cross referencing, making sure the plants grow in our climate zone (Sunset zone 14 or 15 or USDA Zone 9). But, you should be able to come up with plants that will do great for both shade and privacy. 

Fall is the best time to plant in our area when air temperatures are cooler but the soil is still warm. The plants will have some time to get established and winter rains will help with soil moisture. In spring, the plants will have a better chance of growing well.

Please don't hesitate to contact us again if you have more questions.

Help Desk of the UC Master Gardener Program of Contra Costa County (SEH)

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Note: The  UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions.  Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone:  (925) 608-6683,  email: ccmg@ucanr.edu, or on the web   at http://ccmg.ucanr.edu/Ask_Us/  MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Biog  (//ucanr.edu/blogs/CCMGBlog/)

Help for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County

IMPORTANT NOTICE: We are moving to Concord.  Our Pleasant Hill location is now closed.  We expect to reopen in Concord on Monday, 8/6.  Our new address and phone number are:. 

UC Master Gardener Program of Contra Costa County
University of California Cooperative Extension
Contra Costa County
Effective 8/6/18, our new address:
2380 Bisso Lane
Concord, CA 94520

and
UC Master Gardener Program Help Desk
Monday-Thursday, 9:00 AM - 12 Noon
Effective 8/6/18, our new phone number:  
Tel: (925) 608-6683

Remaining the same: 
Email address:  ccmg@ucanr.edu
Website:  http://ccmg.ucanr.edu  
Find us on Facebook:  www.facebook.com/CoCoMasterGardeners

Help Desk Client's Request:  Three of my Ceanothus Geiseus Horizontalis ‘Diamond Heights' (aka Diamond Heights Carmel Creeper) are turning brown. Tons of brown leaves are falling off. As you can see from the first picture, the one on the left is fine for the most part, but the one on the right is not. The second picture is a closer look of one of the plants with a lot of brown leaves. I increased the watering time from 17 to 22 minutes 4x/week about 2 week ago. This plant gets full sun all day and I live in Concord, CA. Here we get daytime temperatures above 85^oF most of the summer. At times we have temperatures above 90^oF degrees for several days. I can't tell for sure, but it is possible the one doing well may have a 2-gallon/hour drip and the others may have a 1-gallon/hour drip. I made sure all of them are being watered. What do you recommend in terms of watering? Should I make sure all of them have a 2-gallon/hour drip? Should I trim the very dry branches? Thank you

MGCC Help Desk Response:  Thank you for contacting the UC Master Gardener Program Help Desk with your plant question. You are seeing your Ceanothus griseus horizontalis 'Diamond Heights' turning brown. Unfortunately, this specific ceanothus is not well adapted to the hot summers we experience in Concord (also Central and East County). The plant was originally found in the Diamond Heights neighborhood in San Francisco, and is best grown in conditions like you find in SF: cool and foggy. Along the coast it tolerates full sun, but further inland it requires shade. They also prefer well-draining soil and moderate water.  

The brown leaves are an indication the plants have not been getting enough water. If the plant getting twice as much water is doing well, you should be applying that much water to all plants of the same variety. It is best to apply the water less often than four times a week. By applying more at one time, it will go deeper into the soil. Since you are currently watering 4 times a week, multiply the time you water by 4 to get the length of time you need to water once a week.  A 2 foot wide Ceanothus 'Diamond Heights' needs at least a gallon of water per week during the hot summer. A 3 foot wide plant would need about a gallon and a half per week. Reduce that amount when the weather cools by watering less frequently, not by cutting the length of time you water.

Dead branches can be pruned out. Check the branch to make sure it's dead before you cut, though. Scrape off a little bark; you should see a greenish wood if it's actually alive. If you see brown or dark tan, the branch is dead.

I hope this information is helpful. Please let us know if you have more questions.

Help Desk of the UC Master Gardener Program of Contra Costa County (SEH)

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Note: The  UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions.  Except for a few holidays, and after our relocation August 6th, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at ,2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone:  (925) 608-6683 , email: ccmg@ucanr.edu, or on the web   at http://ccmg.ucanr.edu/Ask_Us/  MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Biog  (http://ucanr.edu/blogs/CCMGBlog/)